In the related art, in order for a projection device such as a projector to properly project even if the projection surface is a curved surface, there are techniques of determining the correspondence between projection pixels of the projection device and captured image pixels of an imaging device capturing an image of the projection surface and correcting based on the correspondence and projecting a projection image (for example, see Unexamined Japanese Patent Application Publication No. 2015-173431).
Generally, when a projection image is corrected and output as disclosed in the Unexamined Japanese Patent Application Publication No. 2015-173431, a projection image reduced in size to a projection area over which the projection device can project is projected for keeping the aspect ratio of the projection image. Therefore, a problem is that wasted space in which no projection image is projected occurs within the projection area.